ATL: GRACE - Remnants - Discussion

[captainbarbossa19]

Looks like Grace is starting to get a lot better organized today. I would not be surprised if she ends up being our first major at some point.

[NXStumpy_Robothing]

Looks like Grace is starting to get a lot better organized today. I would not be surprised if she ends up being our first major at some point.

Agreed, but admittedly, Grace has had multiple occasions over the past few days where it has looked relatively healthy on satellite; however, there was not much to discuss at the surface. We'll see if that's the case again, but it certainly appears more healthy than it ever has been (aside from that one morning where it looked to be on the brink of some serious intensification, only to get decoupled). Going to have to wait on recon to confirm that, however.

Not a good sign for the Yucatan Peninsula and the western Gulf Coast if this thing can manage to avoid significant disruption from Hispaniola, like what it appears to be doing at the moment.

[Iceresistance]

She is the most impressive since her formation in the Western MDR

[Category5Kaiju]

The one thing I am definitely noticing that seems to be different than when Grace initially formed is the banding. When Grace formed, it looked like a vigorous blob, but in terms of organization, banding is something that is more important. I remember when Elsa looked very vigorous near Jamaica but was found to be very weak and with a high pressure; that too did not really feature good banding but was instead a very healthy looking round blob.

[Sciencerocks]

[Hammy]

Check out those winds whipping around western Haiti, that looks like it might help the inflow get going and help Grace consolidate once it passes Haiti and Jamaica as we saw with Elsa.

[GCANE]

Air is destabilizing quickly in the W Carib
Seeing CAPE up to 4500

[Sciencerocks]

[captainbarbossa19]

https://imagizer.imageshack.com/img923/5841/Qzrtrs.gif

Looks like shear may already be beginning to decrease. I see lots of cirrus moving towards the W and NW from the center now.

[AerospaceEng]

Why is there such a long period with no recon? Seems crazy.

[Iceresistance]

Why is there such a long period with no recon? Seems crazy.

CoC is very close to land . . .

[ElectricStorm]

So uh, ADT must be on some crack. It's got this as a T4.0 hurricane

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.0
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 16 AUG 2021 Time : 223020 UTC
Lat : 17:57:31 N Lon : 72:43:07 W


CI# /Pressure/ Vmax
4.0 / 987.7mb/ 65.0kt


Final T# Adj T# Raw T#
4.0 4.1 4.3

[Nimbus]

https://imagizer.imageshack.com/img923/5841/Qzrtrs.gif

Looks like shear may already be beginning to decrease. I see lots of cirrus moving towards the W and NW from the center now.

Looks like the two centers recon found much earlier are exiting Hispaniola.
Jamaica may consolidate the circulation, competing centers have been keeping the intensity down.
Then we can check the upper air forecast for shear and steering.
Someone said the large high that will be steering this west may center a little further east in response to pumping by Henri.

[TallyTracker]

So uh, ADT must be on some crack. It's got this as a T4.0 hurricane

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.0
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 16 AUG 2021 Time : 223020 UTC
Lat : 17:57:31 N Lon : 72:43:07 W


CI# /Pressure/ Vmax
4.0 / 987.7mb/ 65.0kt


Final T# Adj T# Raw T#
4.0 4.1 4.3

That is hilarious! NHC says depression and ADT says hurricane…if we merge the data does that support 60 mph?

[Blown Away]

Is the Bay of Campeche ever not favorable for hurricane development during the season?

[cycloneye]

A. 07L (GRACE)

B. 16/2330Z

C. 18.0N

D. 72.8W

E. THREE/GOES-E

F. T2.5/2.5

G. IR/EIR/SWIR

H. REMARKS...6/10 BANDING RESULTS IN A DT OF 3.0. MET IS 2.0 BASED ON
A DEVELOPMENT TREND OVER THE PAST 24 HOURS. PT IS 2.5. FT IS BASED ON
PT SINCE THE BANDING WAS NOT CLEAR CUT AND A PATTERN ADJUSTMENT WAS MADE.

I. ADDL POSITIONS

NIL


...COVERDAL

[Bhow]

Is the Bay of Campeche ever not favorable for hurricane development during the season?

Yep last time was August 12, 1849

[SconnieCane]

Is the Bay of Campeche ever not favorable for hurricane development during the season?

Not because of thermodynamics, that's for sure.

It was said that Harvey would have issues with dry air off of Mexico and it sort of did - briefly.

[ElectricStorm]

So when's the next recon mission going out? It sure has been a while

[aspen]

So when's the next recon mission going out? It sure has been a while

These recon gaps with Grace are so unusual for the NHC, and VERY unhelpful when the system is already so difficult to forecast. However, I think they might be avoiding recon due to how close Grace is to the really tall mountains of the Haitian peninsula.